Since goblins are obviously sentient beings surely some, a few at least, would find that they dislike fighting and war although, if we believe recent cinema, they exist for it. I try to imagine what that life would be like. Such an outlier might have to be "re-educated" to the correct mindset and pressed into service against his will, his mane cropped and tied so it can't be grabbed in combat, his armor permanently adhered to his body, his hearing forever sealed so he can listen neither to whispers of rebellion nor to pleas of the vanquished.